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Due to excessive elongation of the eyeball, myopia-related vascular abnormalities are frequently observed in the central retinal artery (CRA) and its intraretinal branches. In addition to inconsistency in previously reported findings, hemodynamic (reduced flow velocity, increased vascular resistance) and morphological changes (narrower vessel diameter) were usually studied separately. This cross-sectional study evaluated the hemodynamic and morphological characteristics concurrently in a large sample of healthy myopes, by using the color Doppler ultrasound and adaptive optics retinal camera. Results showed that the retrobulbar segment of CRA had a tendency of slightly reduced flow velocity in eyeballs with longer axial length, but the correlation was not significant after adjusting for the multiple correlations. Vascular resistance was not affected by the axial elongation. With respect to the intraretinal branches, no significant changes in longer eyes of total diameter or lumen diameter were observed, while both the wall thickness and the wall cross-sectional area were significantly increased, but only a marginally increase in the wall to lumen ratio was found with increasing axial length. This implies some potential small artery remodeling in the intraretinal CRA branches. Overall, blood supply of the inner retina in healthy young myopes is likely to be maintained. Additionally, morphological parameters of vascular microstructure could be potential biomarkers to monitor myopia progression and understand myopia-related vascular abnormalities in future studies.

The short-form Physiological Profile Assessment (PPA) is increasingly used in clinical practice for assessing fall risk in older people. However, a normative database is only available for Caucasian populations. The purpose of the present study was to develop a normative database for Hong Kong Chinese older people and examine the fall risk profile of this population.A total of 622 participants aged 60-95 years were recruited. Participants underwent the PPA (containing tests of contrast sensitivity, proprioception, quadriceps strength, reaction time and sway), and composite fall risk scores were computed. Participants were then followed up for falls for 1 year.Quadriceps strength and lower limb proprioception scores were comparable with those reported for Caucasian populations. However, contrast sensitivity, simple reaction time and postural sway scores were relatively poor. The average composite fall risk score was 1.7 ± 1.5, showing a "moderate" fall risk when compared with the Caucasian norms. Despite the relatively poor physical performances and moderately high fall risk scores, the incidence of one plus falls in the 1-year follow-up period was just 16.4%, with just 2.6% reporting two plus falls. The area under the curve for composite fall risk scores in discriminating fallers from non-fallers was 0.53 (95% CI 0.45-0.60).Despite poorer performance in PPA tests, the incidence of prospective falls in a Hong Kong Chinese population was low. In consequence, the PPA could not discriminate well between fallers and non-fallers. The present study provided normality data for short-form PPA measures for older Chinese people as a reference for further studies.

Cerebral deficit has been implicated in the genesis of strabismus and in the mechanisms adopted to compensate for the visual disorder. Voxel-based morphometry (VBM) was applied to magnetic resonance images of strabismic adults to detect any abnormal brain anatomy, which could not be easily identified by simple inspection. The gray matter volume in strabismic adults was smaller than that in normal subjects at the areas consistent with the occipital eye field (OEF) and parietal eye field (PEF). However, greater gray matter volume was found in strabismic adults relative to normal controls at the areas consistent with the frontal eye field (FEF), the supplementary eye field (SEF), the prefrontal cortex (PFC), and subcortical regions such as the thalamus and the basal ganglia. These opposite gray matter changes in the visual and the oculomotor processing areas are compatible with a hypothesis of plasticity in the oculomotor regions to compensate for the cortical deficits in the visual processing areas.

Experiments upon muscular fatigue in [Formula: see text]-year-old rainbow trout (Salmo gairdneri) were carried out at the trout hatchery at Summerland, British Columbia during the summers of 1958 and 1959. Observations were made on hemoglobin, water content of muscle and whole blood, muscle and liver glycogen, and pyruvate and lactate in muscle, blood and liver. Experimental conditions included 30 min moderate activity, 2–15 min severe exercise, and recovery up to 24 hr following 15 min severe exercise. The results for hemoglobin, muscle and liver glycogen and blood lactate were similar to those reported earlier. Muscle glycogen was depleted 50% or more in the first 2 min of severe activity. Correlated with this rapid depletion of glycogen was a sudden accumulation of muscle pyruvate and lactate. Pyruvate and lactate likewise increased in the blood. While the disappearance of both pyruvate and lactate from muscle began immediately upon cessation of activity, resting levels were not approached until the 8th hr of recovery. During recovery, the levels of pyruvate and lactate in the blood after severe exercise continued to increase for the first hour, remained elevated for at least 8 hr and did not return to the resting level until the 12th–24th hr. Muscle glycogen was not restored above half the resting level at the end of 24 hr. Interpretations of the data in relation to metabolism in rainbow trout are discussed.